As wireless charging matures, a common question emerges: Can ambient RF (Radio Frequency) energy be harvested to charge a smartphone? This post explains the basics of RF energy harvesting, what’s realistically possible today, and where the technology shines. What Is RF Energy Harvesting? RF energy harvesting converts electromagnetic waves from Wi-Fi, cellular base stations, radio, and TV into small amounts of electrical power. An antenna captures RF signals, an impedance-matching network maximizes transfer, and a rectifier converts AC to DC. The output is stored in a capacitor or rechargeable cell and powers ultra-low-power electronics. How Much Power Is Actually Available? Ambient RF levels drop rapidly with distance. In typical urban indoors, harvestable power is often in the nanowatt to microwatt range—orders of magnitude below the watt-level power required for phone charging. This gap means ambient RF alone is not a practical phone-charging method . When Could It W...

Key ingredients used in ice cream—often considered simple and inexpensive—have surged more than 50% in price recently. This directly impacts consumer prices, making it harder to find affordable options. 1. Causes of Ingredient Price Hikes Milk powder, sugar, and emulsifiers are core ingredients whose prices have increased globally. Countries like Japan, the U.S., and China have experienced supply bottlenecks, driving prices up. Anyone checking historical price indices will notice a significant upward trend. 2. Inefficiency in Supply Methods Most domestic ice cream manufacturers rely on contract farming or long-term supplier agreements . However, global supply disruptions and rising fuel prices make immediate adaptation difficult, leading to unavoidable price transfers. 3. Rising Cold Chain and Electricity Costs Ice cream production and distribution depend entirely on cold storage and logistics . Recently, increased electricity rates and fuel costs have driven up storage e...

As smart key systems become more widespread, the security vulnerabilities of car remotes can no longer be ignored. This post systematically explains key hacking methods, real-world cases, and prevention strategies you should know. 1. Types of Car Remote Security Vulnerabilities Relay Attack: Hijacking the signal to make the car believe the key is nearby RollJam Attack: Disrupting rolling codes to reuse previously captured codes Fixed Code Replay: Replicating a static code captured from older remotes CAN Bus Attack: Exploiting internal vehicle network vulnerabilities through OBD-II port 2. Recent Hacking Cases London, UK (2020): Hundreds of BMW and Mercedes vehicles stolen via relay attacks Munich, Germany (2021): Luxury SUVs hijacked using RollJam during the night Seoul, Korea (2022): Relay attacks suspected in valet garages of high-end Hyundai and Kia models USA (2023): Smart key cloning kits openly sold on black markets and online forums...

1. Etymology and Introduction of Jajangmyeon Jajangmyeon originated from the Chinese Shandong dish "Zhajiangmian (炸酱面)." However, what we know today as Korean jajangmyeon is quite different from its Chinese predecessor. The name “jajangmyeon” means “fried (炸) sauce (酱) noodles (面),” referring to noodles topped with stir-fried chunjang (black bean paste). 2. Characteristics of Korean Jajangmyeon Korean jajangmyeon features chunjang fried with sugar, caramel, and onions for a sweeter and deeper flavor , unlike its Chinese counterpart. The noodles are soft yet chewy, making it a popular casual dining option across Korea. 3. Birth of Korean Jajangmyeon at Gonghwachun in Incheon Korean jajangmyeon was first created at “Gonghwachun,” a Chinese restaurant in Incheon in 1905. It was initially served as a cheap, filling meal for laborers. Later, it spread nationwide and became the representative dish of Korean-style Chinese cuisine. 4. Why Is There No Jaj...

Eating salad for health? Then you might be concerned about the sugar and additives in store-bought dressings . Homemade dressings use simple ingredients and can be customized to your taste — healthier and tastier. In this post, I’m sharing six low-sugar, low-calorie, additive-free salad dressing recipes you can easily try at home. 1. Basic Balsamic Oil Dressing Ingredients: 2 tbsp olive oil + 1 tbsp balsamic vinegar + pinch of salt & pepper Notes: A classic, flavorful combo that suits all types of salads 2. Lemon Yogurt Dressing Ingredients: 2 tbsp plain yogurt + 1 tbsp lemon juice + 1 tsp honey + pinch of salt Notes: Light and refreshing — perfect with chicken breast salad 3. Sesame Soy Dressing (Korean-style) Ingredients: 1 tbsp sesame oil + 1 tbsp soy sauce + 1 tbsp vinegar + 1 tbsp sesame seeds Notes: Nutty and savory, pairs well with tofu salad 4. Avocado Creamy Dressing Ingredients: 1/2 mashed avocado + lemon juice + olive o...

Does Your Circuit Breaker Trip After Installing an Induction Cooktop? High-power induction cooktops require more electricity than standard outlets can provide. Especially built-in models with 2 or 3 burners can consume up to 3kW or more . This often exceeds the home's contracted electricity capacity . In such cases, an electric power upgrade is necessary. 1. Electrical Requirements for Induction Cooktops Voltage: 220V Current: At least 15A (usually 20–30A) Dedicated Circuit: Required (no sharing with other appliances) Breaker: Circuit breaker and separate wiring are essential 2. How to Check Your Home's Electrical Capacity Visit Kepco Cyber Branch , log in, and check the “Contract Type and Capacity” section. Most homes have a default contract of 3kW (15A) or 4kW (20A) . To run an induction cooktop smoothly, you need at least 5kW . 3. How to Request a Power Upgrade Call Kepco Customer Center (123 without area code) or request o...

As the digital currency era dawns, Central Bank Digital Currency (CBDC) and private mobile payment platforms like Toss and KakaoPay are faced with a pivotal question: will they compete or collaborate? In this post, we analyze each system’s strengths, strategies, and future roles.     📷 Visual Preview: KakaoPay’s Mobile Payment Interface Image Title: KakaoPay Payment Screen with Barcode & QR Source: Pinterest (royalty‑free screenshot) 1. Central vs. Private Payment Architecture CBDC is centrally issued and regulated by the central bank, whereas KakaoPay and Toss are decentralized private services focusing heavily on user experience. This fundamental difference impacts control, scalability, and trust. CBDC: Centralized, government-backed, legal tender reassurance Private Payment: UX-focused apps with rapid innovation cycles     2. Public Utility vs. Convenience Functionality Each side brings clear ad...